1. Field of the Invention
The present invention relates to an optical apparatus including a barrier member for protecting an optical system and a hood member (eyecup member) adapted to contact a viewer.
2. Description of the Related Art
In general, an optical apparatus such as a telescope (binoculars, monocular, and others) is constructed such that an objective and an eyepiece are set at the front and rear end portions of a lens barrel in an exposed state. In this state, the telescope incurs attachment of dust, greases or the like on the surfaces of the lenses, if it is left as is when not in use, so that there is a possibility of damage to the lenses when the attached dust or the like is removed therefrom. For this reason, lens caps have been used as lens protective members for the objectives and eyepieces of the right- and left-hand lens barrels.
Since the lens cap is fitted over the barrel circumferential surface only under contact pressure, there is a possibility that it easily may be removed therefrom by an external force or the like. For preventing such removal, there has been proposed an optical apparatus in which one end of the lens cap is connected through a string-like member to the barrel body.
In addition, if the optical apparatus such as binoculars, a monocular or a telescope is used in the daytime, unwanted light such as sunlight comes in from the eyepiece side, making viewing difficult. Accordingly, an eyecup (viewing opening) forming a hood member is commonly mounted on the aforesaid optical apparatus.
However, in the case of the above-mentioned conventional optical apparatus in which the lens cap is connected through a string-like member to the barrel body, it becomes hard to handle because the lens cap is unstable while being removed and presents an appearance that is unacceptable. Additionally, when a person wearing spectacles uses the conventional optical apparatus where the eyecup is set upright, this requires shifting the eyecup because the distance between the viewer's eyes(s) and the eyepiece(s) becomes great, making viewing difficult. As with removal of the lens cap, operation of the eyecup overlap becomes troublesome and makes observation hard.